<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link href="assets/css/site.css" rel="stylesheet" type="text/css">
    <style type="text/css">
        div{
            width:100px;height:50px;
        }
    </style>
</head>
<body>
    <div class="bg-red">盒子模型1</div>
    <div class="bg-blue">简单测试</div>
    <a  href="" class="text-red">超链接</a>
<div>
    animation: myfirst 5s;
    -webkit-animation: myfirst 5s; /* Safari 与 Chrome */


</div>


</body>
</html>